This invention relates generally to apparatus for preventing theft of an automotive vehicle and, more particularly, is directed to a mechanical device which prevents a thief from steering the vehicle after break-in and starting of the engine.
In order to prevent theft of an automobile, conventional steering wheel columns provide a spring which biases a locking pin into a slot in a steering wheel locking plate in the column. The locking pin is biased against the spring and out of engagement with the steering wheel locking plate in response to turning on of the ignition. Thus, when the automobile is parked and the ignition is off, although the thief can start the automobile by "hot-wiring" the same, the steering wheel cannot be rotated since the locking pin is biased into the slot in the steering wheel locking plate. In other words, only when the key is placed in the ignition and the ignition is turned on, will the locking pin be removed from the slot in the steering wheel locking plate.
However, when a thief goes to steal an automobile, he generally breaks the outer casing of the steering column at the left side thereof and removes the spring. This, in turn, causes the locking pin to drop down out of the slot in the steering wheel locking plate and thereby free the steering wheel for movement. Then, the automobile can be driven.
Other devices have been suggested for preventing theft of an automobile. For example, U.S. Pat. No. 1,168,701 to Babbitt discloses a locking bolt which can be moved into a recess in the steering shaft. When the ignition key is turned to park the car, the inner shaft or locking cylinder of the ignition is removed from a recess in the locking bolt so that a spring biases the locking bolt into a recess in the steering shaft so as to prevent rotation of the same. With this device, however, it is only necessary for the thief to remove the ignition from the steering column, and insert a tool therein to bias the locking bolt against the spring to free the steering shaft for rotation. Generally, removal of the ignition is a relatively minor matter which can be performed in a short period of time.
U.S. Pat. No. 4,759,203 to Lieb et al. discloses a steering and ignition lock for an automobile in which a latch bolt is moved by the inner shaft of the ignition into a recess of the steering column of the automobile. As with Babbitt, a spring normally biases a control body attached to the latch bolt so as to bias the latch bolt into the recess of the steering column. Thus, with respect to locking of the steering column, this patent is identical in its relevant aspects to Babbitt.
U.S. Pat. No. 4,658,610 to Weber discloses a cylinder lock which is similar in relevant aspects to Babbitt. Specifically, two bolts which are controlled by the inner shaft of the ignition are biased by springs into engagement with gear teeth on a bushing which is non-rotatably disposed on the steering shaft. Therefore, as with Babbitt, a thief can easily, after removing the ignition, merely bias the locking bolts against the springs so as to permit rotation of the steering shaft.
U.S. Pat. No. 2,155,064 to Sandberg; U.S. Pat. No. 3,723,682 to Pecott; and U.S. Pat. No. 4,232,537 to Plaiss disclose other known arrangements which are even more remote than the aforementioned patents.